Generally, projectors include a cooling device for cooling an installed lamp. A fan is widely used as the cooling device.
JP-A No. 2003-215706 discloses a lamp unit including a reflector with a lamp located at its focal point and a holder for holding the open end of the reflector. The open end of the reflector is covered with a transparent plate for preventing fragments from being scattered around in the event that the lamp blows up.
The holder has an inlet port for introducing air into the reflector and an outlet port for discharging air from the reflector. When cooling air from a fan disposed outside of the reflector is introduced from the inlet port into the reflector and air in the reflector is discharged from the outlet port, an air flow (cooling air flow) is developed in the reflector, and impinges upon the lamp to cool the lamp.